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1998 C8 SCT Starbright vs new C9.25 XLT SCT Visual only

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#51 rmollise

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Posted 24 May 2021 - 09:57 AM

Has anyone done a visual observing comparison between a C8 SCT with Starbright coatings and a C9.25 SCT with XLT coatings?  Visual only, please.

 

I have read all I can find on CN and see many opinions and theories and quoted numbers, but haven't found anyone who said that they actually looked through both enough to know if the C9.25 XLT enables someone to see any more detail or any more faint objects visually when compared to an older C8 with only Starbright coatings.

 

I read that moving from Starbright coatings to XLT coatings in the same OTA size is barely noticeable.  I also read that moving from an 8 inch SCT to a 9.25 inch SCT is barely noticeable. (that you really need to step to an 11 inch to get any significant impact)

 

I have a 1998 C8 Starbright SCT and might have the opportunity to replace that with a new C9.25 XLT SCT.  Although the OTA price is good, I would need the larger dew shield, heater strip and case, so there is still a lot of money involved.

 

I am a visual observer only.  What difference, if any, good or bad, will I see in my eyepiece if I make the change?

 

I use an EQ6-R mount so have no issue with the weight. I know I will lose some field of view. With my C8, I use 1-1/4 and 2 inch eye pieces with and without a focal reducer, and use both a 2" Baader BBHS Mirror diagonal and a BBHS T2 prism diagonal.

 

Thanks, Gary

 

 

The difference is not at the knock-your-socks-off level. But it is there. If you must observe from compromised skies, do yourself a favor and get the 9.25. The extra aperture will do more for you than improved coatings. ;)


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#52 gnowellsct

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Posted 24 May 2021 - 11:35 AM

I don't disagree with anyone who suggests the 9.25 is a better option.  Particularly for one-scope-ism.  For my purposes these days I'm enjoying the c8.

 

There probably is as much to be gained in a mount upgrade as there is to be gained in an OTA upgrade, however.  The G11 easily handles the 9.25.  Very sweet combination.   It just so happens I use it with c8 + apo.  I also use the G11 for all my refractors in various combinations.   I think the Losmandy tripod instead of the Berlebach shown might be better for 9.25, it depends on one's particular circumstances.  Most of my viewing is on grass surfaces, I can drive the surveyors' spikes in deep and get a real solid "planting."  If you can't do that the Losmandy tripod is a better deal.

 

For c14 + apo I use an old AP900QMD.  (non-go-to AP900)   In terms of your moving to two inch eyepieces, etc., this is all good.  I customized the rear end of my c8: AP diagonal, AP visual back, etc.

 

 

c8 with stowaway.jpg


Edited by gnowellsct, 24 May 2021 - 11:56 AM.

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#53 gnowellsct

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Posted 24 May 2021 - 12:05 PM

Customized butt end of c8.  It may be some day that WWIII will happen and I'll be nuked while observing.  But they will find in the molten slag my XW 40 locked in forever embrace with the AP diagonal and custom AP visual back.   The plastic fine focus knob, on the other hand....

 

Note the ribs on the rear casting.  This is 2015 XLT optics in the carcass of a circa 1989 c8.  The optics transplant was like night and day, to my eye anyhow, and that's a c8 to c8 comparo.  The 1989 scope was one I had injured with various "medical experiments" and which I was indifferent about keeping in any case, even before the experiments.  The new optics turned the scope from something that sat in the garage to a regular feature of my observing.

 

China optics too.  I am generally not a fan of China's industrial output.  But I have to say that on an average day the mainland China Celestron sct factory might now be doing as well as the old Torrance facility on a really great day.

 

GN

 

c8 visual back in the field.jpg


Edited by gnowellsct, 24 May 2021 - 12:09 PM.


#54 GGK

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Posted 25 May 2021 - 08:01 AM

I don't disagree with anyone who suggests the 9.25 is a better option.  Particularly for one-scope-ism.  For my purposes these days I'm enjoying the c8.

 

There probably is as much to be gained in a mount upgrade as there is to be gained in an OTA upgrade, however.  The G11 easily handles the 9.25.  Very sweet combination.   It just so happens I use it with c8 + apo.  I also use the G11 for all my refractors in various combinations.   I think the Losmandy tripod instead of the Berlebach shown might be better for 9.25, it depends on one's particular circumstances.  Most of my viewing is on grass surfaces, I can drive the surveyors' spikes in deep and get a real solid "planting."  If you can't do that the Losmandy tripod is a better deal.

 

For c14 + apo I use an old AP900QMD.  (non-go-to AP900)   In terms of your moving to two inch eyepieces, etc., this is all good.  I customized the rear end of my c8: AP diagonal, AP visual back, etc.

 

 

attachicon.gifc8 with stowaway.jpg

Nice set-up.

 

I often sit in sandy soil and I find that no matter how hard I plant the tripod feet initially, the spike toes settle in over a few hours taking the mount out of alignment.  Even the Celestron vibration suppression discs settle in a little though the night.  Now I put 6 inch square pieces of wood under the tripod feet.


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#55 gjanke

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Posted 25 May 2021 - 10:41 AM

Your welcome. Everybody is entitled to their opinion. Unfortunately, public forums are often filled with opinion rather than facts. The OP, I presume, is here for fact based information. I could be wrong.

 

The EQ6R is what the OP says that he has. If you are aware that the EQ6R and the GCEM are alike, then why tell him he needs a better mount? I am sure that thinking he might need to drop another $2000 is unsettling, at the least. Not sure what it has to do with the weather.

 

I said "nonsense" to your inference that the difference between the two is so small that the evening seeing could impact your ability to ascertain any difference whatsoever. Nonsense. I've looked through the two side by side. Have you?

 

Yes, I really mean everything that I stated.

So to be clear the Topic Starter asked for opinions of people that have used these scopes in a variety of use cases and was soliciting for their thoughts. No where was it stated he wanted metric drive data points about these observations.

 

The only criteria was; you were a visual user and had tried the various configurations which I have had done on numerous occasions.  

 

Really all you offered in this exchange is your opinion and not a single fact. Which you are more than welcome to and I enjoy reading yours and others.

 

However, I understand we live in the age of outrage but really dude you need to check yourself and dial back the acerbic tone. Unsettling?! really? People dying of COVID is unsettling me suggesting a 2k mount upgrade is more in line with askew.

 

Anyway,

 

Clear skies




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